When manufacturers decided there needed
to be ammunition between .22 WMR and .223 caliber, the .17 HMR was
born. The .22 WMR was produced since 1959 and magnums became more
popular than the old standby .22LR because it fired at a higher
pressure and its bullet was jacketed instead of soft lead. However,
even the .22 WMR was a pain to load into auto-loading, magazine fed
rifles, so Hornady produced the .17 HMR.
